1. Field of the Invention
The present invention relates to a plant-growing method aiming at greening upright or slant wall surfaces of buildings or structures by means of trees.
2. Description of the Related Art
In the conventional methods of greening buildings, it is well known to cover the wall surfaces with ivy or to plant trees into the soil deposited on the wall surfaces. It is also known, in U.S. Pat. No. 5,257,476, issued to the present inventor, to prepare a plurality of bags loaded with soil, to pile them on the wall surfaces of the building and to insert trees' roots between the piled bags to plant trees.
However, the above method using ivy has a restriction that due to the nature of the ivy, the area and shape to be greened are not accurately defined, which results in an insufficient greening of the building. On the contrary, the method depositing soil on a wall surface requires problematic means for containing the soil to be deposited. For this reason, deferring from use of a simple case greening the window and its vicinity by use of planters or pots, it was necessary for large-scale greening to provide overhangs or frameworks for the soil containers. Accordingly, this method disadvantageously needed a large-scale reconstruction of wall surfaces of the building or structure, or alternatively a framework construction. It was also inconveniently necessary for the workers to climb up every maintenance or replanting period since the trees were fixedly located on the wall surfaces and to provide scaffolds for that work. This makes it substantially impossible to apply such a method to skyscrapers. Even the invention disclosed in the above-mentioned U.S. Pat. No.: 5,257,476 requires lattice fences for bearing the piled bags along the wall surfaces of the building. Consequently, what is desired is a method of greening the building free from such necessity for the lattice fences.